Allow to add Date header to the request.

webcc/utility.h

@@ -4,14 +4,25 @@
 #include <string>
 
 namespace webcc {
+namespace utility {
 
+// Get a randomly generated UUID.
 std::string RandomUuid();
 
+// Get default user agent for HTTP headers.
+const std::string& UserAgent();
+
+// Get the timestamp for HTTP Date header field.
+// E.g., Wed, 21 Oct 2015 07:28:00 GMT
+// See: https://tools.ietf.org/html/rfc7231#section-7.1.1.2
+std::string GetTimestamp();
+
 // Split a key-value string.
 // E.g., split "Connection: Keep-Alive".
 bool SplitKV(const std::string& str, char delimiter,
              std::string* key, std::string* value);
 
+}  // namespace utility
 }  // namespace webcc
 
 #endif  // WEBCC_UTILITY_H_